1. Field of the Invention
The present invention relates to a vehicle interior illumination device in a vehicle.
2. Description of the Related Art
Recently, a personal lamp that can be used, for example, by a passenger sitting on a rear seat is set on a roof, a pillar or the like in a vehicle. The personal lamp is an illumination lamp that illuminates the rear seat. The personal lamp is lit not only when a lighting switch operated by a passenger at the time of reading but also when a door switch detecting that a rear seat side door is open is turned on or a seat belt switch detecting that a seat belt is not fastened is turned on. This illumination by the personal lamp is called functional illumination.
Moreover, a related art discloses that when the entire vehicle interior is illuminated by a monitor attached to a ceiling of a vehicle interior, light is emitted with a variable light amount and color shade and the vehicle interior is garnished with an illumination matching the mood of the passengers or the like and the atmosphere (see JP-A-2006-44567). This illumination is called atmospheric illumination.
However, when an illumination lamp for the atmospheric illumination is set in the vehicle interior, since it is set in addition to an illumination lamp for the functional illumination set on the rear seat side, the number of illumination lamps increases.
Moreover, when an illumination lamp for the atmospheric illumination is provided in addition to an illumination lamp for the functional illumination, it is unclear how to use the functional illumination and the atmospheric illumination each in its proper way. That is, the atmospheric illumination is low in illuminance since it dimly illuminates the vehicle interior in order that the driver confirms the safety of the rear seat while driving or to provide the vehicle interior with a unique atmosphere. On the other hand, the functional illumination is high in illuminance since it is used when a passenger is informed that a door is open or that the seat belt is not fastened or when a passenger performs reading. As described above, the functional illumination and the atmospheric illumination are different in light amount and it is necessary to use them each in its proper way.